It's a Windows Precision Touchpad with a matte glass surface, and it feels pretty good!
There doesn’t seem to be much space left for a large battery. Do you have any estimates on capacity?
We integrated a 55Wh battery, which is pretty typical for 13.5-14" notebooks.
Will the internal layout (and thermal characteristics) allow for a larger battery, perhaps at the expense of ports/expansion slots?
Now I'm curious if extra batteries will be possible to plug into the modules
technically possible as all 4 ports support usb-c PD, but the modules are not big enough to support any reasonable capacity. It is a path to connect something like a slice battery that you could attach to the bottom however!
I've never heard of a "slice battery", but I'm guessing you mean a thin, wedge-shaped battery than would sit underneath the laptop? If so, wouldn't rising heat from the battery be a problem?